This invention relates to an IC card and, more particularly, to an improvement in an IC card suitable for use as a credit card, an identification card or the like.
Recently, an IC card having an inbuilt integrated circuit pellet, such as an IC, LSI or the like, has been developed as a credit card, an identification card and the like. In an IC card of this type, the buried structure of an integrated circuit pellet and its method of construction is as follows. Electrode terminals of the pellet are first connected, by wire bonding, to an insulating base material providing stiff lead wires corresponding to the electrode terminals of the pellet, and a synthetic resin for forming an integrated circuit chip is molded around the pellet. The molded chip is stored in a storing portion of an inner core, and the lead wires are connected to connecting terminals formed on the insulating board. Thereafter, an overcoat is formed on the resultant structure.
However, since the integrated circuit chip is molded in the conventional IC card having the above structure, the lead wires are of a stiff material and are connected between the chip and the board. Thus, the lead wires lack the flexibility to deal with external pressure, resulting in poor mechanical strength and reliability of the IC card. For this reason, if the card is subjected to external pressure or shock, those connecting portions between the lead wires, the chip and/or the board, can be easily damaged.
The conventional IC card has a structure that requires complex manufacturing steps, resulting in high cost. Three bonding processes for electrically connecting the integrated circuit pellet are required, the number of manufacturing steps increasing to include an inner lead bonding, an outer lead bonding and lead connecting.